<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        .box{
            display: flex;
            height: 350px;
            width: 500px;
            border: 1px solid #ccc;
            /* justify-content: flex-start; */
            /* align-items: stretch;  */
            /* stretch 当子元素没有高度时，让子元素和父元素一样高 */
            /* flex-wrap: wrap; */
            /* align-content: stretch; */
            /* flex-direction: column-reverse; */
            /* flex-flow: flex-direction flex-wrap 的简写 */
            /* flex-flow: column-reverse wrap; */
        }
        .inner{
            width: 100px;
            height: 100px;
            color: #fff;
            font-size: 50px;
            text-align: center;
            line-height: 100px;
            background-color: lightseagreen;
        }
        .inner:nth-child(2){
            /* align-self: baseline; */
            /* order: 1; */
            /* flex-grow:1; */
            /* flex-shrink: 0; */
            /*flex-basis 定义弹性元素占据主轴的空间  长度值/auto
                basis > width/height   basis < 元素被内容撑起来的宽高
            */
            /* flex-basis: 30px; */
            /* flex: flex-grow flex-shrink flex-basis 的简写 
            auto ==> 1 1 auto   	none ==> 0 0 auto
            */
            /* flex: none; */
            /* flex: 1; */
            /* flex-basis: 1 1 10%; */
        }
    </style>
</head>
<body>
    <div class="box">
        <div class="inner">1</div>
        <div class="inner">2</div>
        <div class="inner">3</div>
        <div class="inner">4</div>
        <!-- <div class="inner">5</div>
        <div class="inner">6</div>
        <div class="inner">7</div>
        <div class="inner">8</div> -->
    </div>
</body>
</html>